With the development of image processing technologies and mobile terminal devices, a mobile apparatus is used as a photographing apparatus anywhere at any time, and this has become an important function commonly used in daily life. People take photos using a photographing apparatus to conveniently record wonderful moments and express feelings. Currently, most photographing apparatuses (for example, a desktop computer, a mobile phone, a tablet computer, and a camera) provide photographing functions.
A user wishes that a taken photo can effectively reflect a moving trail of a light source for the user, for example, photographing a light-trail pattern that is formed after a handheld light source is moved, a glimpse of fireworks display that easily disappears, or a silky water effect brought by magnificent waterfalls. Currently, photographing quality of a moving trail of a light source is improved mainly using a slow shutter of a single lens reflex camera mounted on a tripod. However, the single lens reflex camera is expensive and is not easy to carry, and a screen of the single lens reflex camera becomes dark during photographing. In this case, the user needs to have rich photographing experience and needs to manually adjust photographing parameters according to a photographing scenario in order to obtain photos having proper exposure and good sharpness. Therefore, based on a current photographing technology, the user cannot really and effectively take a high-quality photo of a moving trail of a light source, and user experience during a photographing process needs to be improved.